Anti-static agent, anti-static agent composition, anti-static resin composition, and molding

ABSTRACT

Provided are: an antistatic agent and an antistatic agent composition which are capable of providing excellent antistatic effect in a small amount and have sufficient persistence and wiping resistance; and an antistatic resin composition and a molded article using the same. 
     The antistatic agent includes a polymer compound (E) having a structure in which a diol, a dicarboxylic acid, a compound (B) which comprises at least one group represented by the following Formula (1) and has hydroxyl groups at both ends, and a polycarboxylic acid compound (D) are bound via ester bonds:
 
—CH 2 —CH 2 —O—  (1).

TECHNICAL FIELD

The present invention relates to improvement of an antistatic agent, anantistatic agent composition, an antistatic resin composition(hereinafter, also simply referred to as “resin composition”) and amolded article.

BACKGROUND ART

Thermoplastic resins are important materials that are indispensable inthe modern world because they not only are lightweight and easy toprocess but also have excellent properties in that, for example, theirbase materials can be designed in accordance with the intended use. Inaddition, thermoplastic resins have excellent electrical insulationproperties and are thus often utilized in the components and the like ofelectrical appliances. However, there is a problem that thermoplasticresins are easily electrically charged by friction and the like becauseof their excessively high insulation performance.

An electrically charged thermoplastic resin attracts dust and dirt inthe surroundings and thus causes a problem of deteriorating the outerappearance of its molded article. Further, among electronic products,for example, in precision instruments such as computers, an electriccharge may interfere with normal circuit operation. Moreover, there arealso problems caused by an electric shock. An electric shock to a personfrom a resin not only causes discomfort but also potentially inducesaccidental explosion in the presence of flammable gas or dust.

In order to solve these problems, synthetic resins are conventionallysubjected to an antistatic treatment. The most common antistatictreatment method is an addition of an antistatic agent to a syntheticresin of interest. Examples of the antistatic agent include coating-typeantistatic agents that are coated on the surface of a resin moldedarticle and kneading-type antistatic agents that are added when a resinis molded; however, the coating-type antistatic agents have poorpersistence, and coating of a large amount of such an organic substanceon a surface leads to a problem that objects coming into contact withthe surface are contaminated.

From these viewpoints, conventionally, kneading-type antistatic agentshave mainly been examined and, for example, the use of polyether esteramide has been proposed for the purpose of imparting antistaticity topolyolefin-based resins (Patent Documents 1 and 2). Further, a blockpolymer having a structure in which a polyolefin block and a hydrophilicpolymer block are repeatedly and alternately bound with each other hasbeen proposed (Patent Document 3).

RELATED ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Unexamined Patent Application PublicationNo. S58-118838

Patent Document 2: Japanese Unexamined Patent Application PublicationNo. H3-290464

Patent Document 3: Japanese Unexamined Patent Application PublicationNo. 2001-278985

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, not only these conventional antistatic agents cannotdemonstrate sufficient antistatic performance unless they are added in alarge amount with respect to a resin, but also their antistatic effectsare not persistent enough. In addition, there is a problem that wipingof the surface of a molded article of the resin causes a reduction inthe antistatic effect. In view of the above, an object of the presentinvention is to provide an antistatic agent and an antistatic agentcomposition which are capable of providing excellent antistatic effectin a small amount and have sufficient persistence and wiping resistance.Another object of the present invention is to provide an antistaticresin composition which has sufficient persistence and wiping resistanceand exhibits excellent antistatic properties. Yet another object of thepresent invention is to provide a molded article composed of athermoplastic resin, whose commercial value is not likely to be reducedby surface contamination or dust adhesion caused by static electricity.

Means for Solving the Problems

The present inventors intensively studied to solve the above-describedproblems, thereby completing the present invention.

That is, the antistatic agent of the present invention is characterizedby comprising a polymer compound (E) having a structure in which a diol,a dicarboxylic acid, a compound (B) which comprises at least one grouprepresented by the following Formula (1) and has hydroxyl groups at bothends, and a polycarboxylic acid compound (D) are bound via ester bonds:—CH₂—CH₂—O—  (1)

In the antistatic agent of the present invention, it is preferred thatthe polymer compound (E) has a structure in which a polyester (A), whichis constituted by a diol and a dicarboxylic acid, the compound (B) andthe polycarboxylic acid compound (D) are bound via ester bonds.

In the antistatic agent of the present invention, it is also preferredthat the polymer compound (E) has a structure in which a block polymer(C) having hydroxyl groups at both ends and the polycarboxylic acidcompound (D) are bound via an ester bond, the block polymer (C)comprising a block constituted by the polyester (A) and a blockconstituted by the compound (B) that are repeatedly and alternatelybound via ester bonds.

Further, in the antistatic agent of the present invention, it ispreferred that the polyester (A) has a structure comprising carboxylgroup at one or both ends. Still further, in the antistatic agent of thepresent invention, it is preferred that the block constituted by thepolyester (A) has a number-average molecular weight of 800 to 8,000 interms of polystyrene; the block constituted by the compound (B) has anumber-average molecular weight of 400 to 6,000 in terms of polystyrene;and the block polymer (C) has a number-average molecular weight of 5,000to 25,000 in terms of polystyrene. Yet still further, in the antistaticagent of the present invention, it is preferred that the compound (B) bea polyethylene glycol. Yet still further, in the antistatic agent of thepresent invention, it is preferred that the polycarboxylic acid compound(D) is a carboxylic acid having three or more carboxyl groups.

The antistatic agent composition of the present invention ischaracterized by comprising at least one selected from the groupconsisting of alkali metal salts and Group II element salts in theantistatic agent of the present invention.

Further, the antistatic resin composition of the present invention ischaracterized by comprising the antistatic agent of the presentinvention or the antistatic agent composition of the present inventionin a thermoplastic resin.

In the antistatic resin composition of the present invention, it ispreferred that the thermoplastic resin be at least one selected from thegroup consisting of polyolefin-based resins, polystyrene-based resinsand copolymers thereof. In the antistatic resin composition of thepresent invention, it is also preferred that the mass ratio of thethermoplastic resin and the antistatic agent or the antistatic agentcomposition be in a range of 99/1 to 40/60.

The molded article of the present invention is characterized by beingcomposed of the antistatic resin composition of the present invention.

Effects of the Invention

According to the present invention, an antistatic agent and anantistatic agent composition, which are capable of providing excellentantistatic effect in a small amount and have sufficient persistence andwiping resistance, can be provided. In addition, according to thepresent invention, an antistatic resin composition which has sufficientpersistence and wiping resistance and exhibits excellent antistaticproperties can be provided. Further, according to the present invention,a molded article composed of a thermoplastic resin, whose commercialvalue is not likely to be reduced by surface contamination or dustadhesion caused by static electricity, can be provided.

MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described in detail.

The polymer compound (E) according to the present invention has astructure in which a diol, a dicarboxylic acid, a compound (B) whichcomprises at least one group represented by the following Formula (1)and has hydroxyl groups at both ends, and a polycarboxylic acid compound(D) are bound via ester bonds:—CH₂—CH₂—O—  (1)

The polymer compound (E) can be obtained by allowing a diol, adicarboxylic acid, a compound (B) which comprises at least one grouprepresented by the Formula (1) and has hydroxyl groups at both ends, anda polycarboxylic acid group (D) to undergo an esterification reaction.

First, the diol used in the present invention will be described.

Examples of the diol used in the present invention include aliphaticdiols and aromatic group-containing diols. Two or more of these diolsmay be used in combination. Examples of the aliphatic diols include1,2-ethanediol (ethylene glycol), 1,2-propanediol (propylene glycol),1,3-propanediol, 1,2-butanediol, 1,3-butanediol,2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol,2,2-dimethyl-1,3-propanediol (neopentyl glycol),2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane),2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylol heptane),3-methyl-1,5-pentanediol, 1,6-hexanediol,2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol,2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol,1,12-octadecanediol, 1,4-cyclohexane dimethanol, hydrogenated bisphenolA, 1,2-, 1,3- or 1,4-cyclohexanediol, cyclododecanediol, dimer diol,hydrogenated dimer diol, diethylene glycol, dipropylene glycol,triethylene glycol and polyethylene glycol. Among these aliphatic diols,1,4-cyclohexane dimethanol and hydrogenated bisphenol A are preferredbecause of their compatibility with thermoplastic resins and antistaticproperties, and 1,4-cyclohexane dimethanol is more preferred.

The aliphatic diols are preferably hydrophobic; therefore, amongaliphatic diols, hydrophilic polyethylene glycols are not preferred.This, however, does not apply to those cases where they are used incombination with other diol.

Examples of the aromatic group-containing diols include polyhydroxyethyladducts of mononuclear dihydric phenol compounds, such as bisphenol A,1,2-hydroxybenzene, 1,3-hydroxybenzene, 1,4-hydroxybenzene,1,4-benzenedimethanol, bisphenol A-ethylene oxide adducts, bisphenolA-propylene oxide adduct, 1,4-bis(2-hydroxyethoxy)benzene, resorcin andpyrocatechol. Among these aromatic group-containing diols, bisphenolA-ethylene oxide adducts and 1,4-bis(β-hydroxyethoxy)benzene arepreferred.

Next, the dicarboxylic acid used in the present invention will bedescribed.

Examples of the dicarboxylic acid used in the present invention includean aliphatic dicarboxylic acid and an aromatic dicarboxylic acid. Thedicarboxylic acid may be a mixture of the aliphatic dicarboxylic acidand the aromatic dicarboxylic acid.

The aliphatic dicarboxylic acid may be a derivative (such as an acidanhydride, an alkyl ester, an alkali metal salt or an acid halide) of analiphatic dicarboxylic acid. Further, two or more aliphatic dicarboxylicacids and derivatives thereof may be used in combination.

The aliphatic dicarboxylic acid is preferably, for example, an aliphaticdicarboxylic acid having 2 to 20 carbon atoms, examples of which includeoxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid,pimelic acid, suberic acid, azelaic acid, sebacic acid,1,10-decanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, dimeracid, maleic acid and fumaric acid. Among these aliphatic dicarboxylicacids, from the standpoints of the melting point and heat resistance,ones having 4 to 16 carbon atoms are preferred, and ones having 6 to 12carbon atoms are more preferred.

The aromatic dicarboxylic acid may be a derivative (such as an acidanhydride, an alkyl ester, an alkali metal salt or an acid halide) of anaromatic dicarboxylic acid. Further, two or more aromatic dicarboxylicacids and derivatives thereof may be used in combination.

The aromatic dicarboxylic acid is preferably, for example, an aromaticdicarboxylic acid having 8 to 20 carbon atoms, examples of which includeterephthalic acid, isophthalic acid, phthalic acid, phenylmalonic acid,homophthalic acid, phenylsuccinic acid, β-phenylglutaric acid,α-phenyladipic acid, β-phenyladipic acid, biphenyl-2,2′-dicarboxylicacid, biphenyl-4,4′-dicarboxylic acid, naphthalenedicarboxylic acid,sodium 3-sulfoisophthalate, and potassium 3-sulfoisophthalate.

Next, the compound (B) used in the present invention, which comprises atleast one group represented by the following Formula (1) and hashydroxyl groups at both ends, will be described.

The compound (B) which comprises at least one group represented by thefollowing Formula (1) and has hydroxyl groups at both ends is preferablya hydrophilic compound, more preferably a polyether having the grouprepresented by the Formula (1), particularly preferably a polyethyleneglycol represented by the following Formula (2):

In the Formula (2), m represents a number of 5 to 250. From thestandpoints of the heat resistance and compatibility, m is preferably 20to 150.

Examples of the compound (B) include polyethylene glycols obtained byaddition reaction of ethylene oxide; and polyethers obtained by additionreaction of ethylene oxide and at least one other alkylene oxide (e.g.,propylene oxide, or 1,2-, 1,4-, 2,3- or 1,3-butylene oxide), which maybe random or block polyethers.

Examples of the compound (B) also include compounds having a structurein which ethylene oxide is added to an active hydrogen atom-containingcompound; and compounds having a structure in which ethylene oxide andat least one other alkylene oxide (e.g., propylene oxide, or 1,2-, 1,4-,2,3- or 1,3-butylene oxide) are added. The addition in these compoundsmay be random or block addition.

The active hydrogen atom-containing compound is, for example, a glycol,a dihydric phenol, a primary monoamine, a secondary diamine or adicarboxylic acid.

As the glycol, aliphatic glycols having 2 to 20 carbon atoms, alicyclicglycols having 5 to 12 carbon atoms and aromatic glycols having 8 to 26carbon atoms can be used.

Examples of the aliphatic glycols include ethylene glycol, 1,2-propyleneglycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol,1,3-hexanediol, 1,4-hexanediol, 1,6-hexanediol, 2,5-hexanediol,1,2-octanediol, 1,8-octanediol, 1,10-decanediol, 1,18-octadecanediol,1,20-eicosanediol, diethylene glycol, triethylene glycol andthiodiethylene glycol.

Examples of the alicyclic glycols include1-hydroxymethyl-1-cyclobutanol, 1,2-cyclohexanediol,1,3-cyclohexanediol, 1,4-cyclohexanediol, 1-methyl-3,4-cyclohexanediol,2-hydroxymethylcyclohexanol, 4-hydroxymethylcyclohexanol,1,4-cyclohexane dimethanol and 1,1′-dihydroxy-1,1′-dicyclohexanol.

Examples of the aromatic glycols include dihydroxymethylbenzene,1,4-bis(β-hydroxyethoxy)benzene, 2-phenyl-1,3-propanediol,2-phenyl-1,4-butanediol, 2-benzyl-1,3-propanediol, triphenylethyleneglycol, tetraphenylethylene glycol and benzopinacol.

As the dihydric phenol, a phenol having 6 to 30 carbon atoms can beused, and examples thereof include catechol, resorcinol,1,4-dihydroxybenzene, hydroquinone, bisphenol A, bisphenol F, bisphenolS, dihydroxydiphenyl ether, dihydroxydiphenyl thioether, binaphthol, andalkyl (C1 to C10) or halogen substitution products of these phenols.

Examples of the primary monoamine include aliphatic primary monoamineshaving 1 to 20 carbon atoms, such as methylamine, ethylamine,n-propylamine, isopropylamine, n-butylamine, s-butylamine,isobutylamine, n-pentylamine, isopentylamine, n-hexylamine,n-heptylamine, n-octylamine, n-decylamine, n-octadecylamine andn-eicosylamine.

Examples of the secondary diamine include aliphatic secondary diamineshaving 4 to 18 carbon atoms, heterocyclic secondary diamines having 4 to13 carbon atoms, alicyclic secondary diamines having 6 to 14 carbonatoms, aromatic secondary diamines having 8 to 14 carbon atoms, andsecondary alkanoldiamines having 3 to 22 carbon atoms.

Examples of the aliphatic secondary diamines includeN,N′-dimethylethylenediamine, N,N′-diethylethylenediamine,N,N′-dibutylethylenediamine, N,N′-dimethylpropylenediamine,N,N′-diethylpropylenediamine, N,N′-dibutylpropylenediamine,N,N′-dimethyltetramethylenediamine, N,N′-diethyltetramethylenediamine,N,N′-dibutyltetramethylenediamine, N,N′-dimethylhexamethylenediamine,N,N′-diethylhexamethylenediamine, N,N′-dibutylhexamethylenediamine,N,N′-dimethyldecamethylenediamine, N,N′-diethyldecamethylenediamine andN,N′-dibutyldecamethylenediamine.

Examples of the heterocyclic secondary diamines include piperazine and1-aminopiperidine.

Examples of the alicyclic secondary diamines includeN,N′-dimethyl-1,2-cyclobutanediamine,N,N′-diethyl-1,2-cyclobutanediamine,N,N′-dibutyl-1,2-cyclobutanediamine,N,N′-dimethyl-1,4-cyclohexanediamine,N,N′-diethyl-1,4-cyclohexanediamine,N,N′-dibutyl-1,4-cyclohexanediamine,N,N′-dimethyl-1,3-cyclohexanediamine,N,N′-diethyl-1,3-cyclohexanediamine andN,N′-dibutyl-1,3-cyclohexanediamine.

Examples of the aromatic secondary diamines includeN,N′-dimethyl-phenylenediamine, N,N′-dimethyl-xylylenediamine,N,N′-dimethyl-diphenylmethanediamine, N,N′-dimethyl-diphenyl etherdiamine, N,N′-dimethyl-benzidine andN,N′-dimethyl-1,4-naphthalenediamine.

Examples of the secondary alkanoldiamines includeN-methyldiethanolamine, N-octyldiethanolamine, N-stearyldiethanolamineand N-methyldipropanolamine.

Examples of the dicarboxylic acid include dicarboxylic acids having 2 to20 carbon atoms, such as aliphatic dicarboxylic acids, aromaticdicarboxylic acids and alicyclic dicarboxylic acids.

Examples of the aliphatic dicarboxylic acids include oxalic acid,malonic acid, succinic acid, glutaric acid, methylsuccinic acid,dimethylmalonic acid, β-methylglutaric acid, ethylsuccinic acid,isopropylmalonic acid, adipic acid, pimelic acid, suberic acid, azelaicacid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylicacid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid,hexadecanedicarboxylic acid, octadecanedicarboxylic acid andeicosanedicarboxylic acid.

Examples of the aromatic dicarboxylic acids include terephthalic acid,isophthalic acid, phthalic acid, phenylmalonic acid, homophthalic acid,phenylsuccinic acid, β-phenylglutaric acid, α-phenyladipic acid,β-phenyladipic acid, biphenyl-2,2′-dicarboxylic acid,biphenyl-4,4′-dicarboxylic acid, naphthalenedicarboxylic acid, sodium3-sulfoisophthalate, and potassium 3-sulfoisophthalate.

Examples of the alicyclic dicarboxylic acids include1,3-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid,1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid,1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanediacetic acid,1,3-cyclohexanediacetic acid, 1,2-cyclohexanediacetic acid anddicyclohexyl-4,4′-dicarboxylic acid.

These active hydrogen atom-containing compounds may be usedindividually, or two or more thereof may be used in combination.

Next, the polycarboxylic acid compound (D) used in the present inventionwill be described.

Examples of the polycarboxylic acid compound (D) include carboxylicacids having three or more carboxyl groups; and carboxylic acids havingtwo or more carboxyl groups and at least one hydroxyl group and, fromthe standpoints of the compatibility with thermoplastic resins and theantistatic properties, carboxylic acids having three or more carboxylgroups are preferred. The polycarboxylic acid compound (D) may be amixture of these carboxylic acids.

The carboxylic acids having three or more carboxyl groups may bederivatives thereof (such as acid anhydrides, alkyl esters, alkali metalsalts and acid halides). The carboxylic acids having three or morecarboxyl groups and derivatives thereof may be used in a combination oftwo or more thereof.

Examples of the carboxylic acids having three or more carboxyl groupsinclude aconitic acid, 1,2,3-propanetricarboxylic acid,butane-1,2,3,4-tetracarboxylic acid, 3-butene-1,2,3-tricarboxylic acid,trimellitic acid, pyromellitic acid, mellitic acid, cyclohexanetricarboxylic acid, naphthalene-1,2,5-tricarboxylic acid,naphthalene-2,6,7-tricarboxylic acid, 1,3,5-pentanetricarboxylic acid,trimesic acid, 3,3′,4-diphenyltricarboxylic acid,benzophenone-3,3′,4-tricarboxylic acid,diphenylsulfone-3,3′,4-tricarboxylic acid, diphenylether-3,3′,4-tricarboxylic acid, diphenyl-2,2′,3,3′-tetracarboxylicacid, benzophenone-2,2′,3,3′-tetracarboxylic acid,diphenylsulfone-2,2′,3,3′-tetracarboxylic acid,diphenyl-2,2′,3,3′-tetracarboxylic acid,benzophenone-2,2′,3,3′-tetracarboxylic acid,diphenylsulfone-2,2′,3,3′-tetracarboxylic acid and diphenylether-2,2′,3,3′-tetracarboxylic acid, and acid-modified polyethylenewaxes, polyacrylic acids and the like that have three or more carboxylgroups can also be used.

The carboxylic acids having two or more carboxyl groups and at least onehydroxyl group may be derivatives thereof (such as acid anhydrides,alkyl esters, alkali metal salts and acid halides). The carboxylic acidshaving two or more carboxyl groups and at least one hydroxyl group andderivatives thereof may be used in a combination of two or more thereof.Examples of the carboxylic acids having two or more carboxyl groups andat least one hydroxyl group include tartaric acid, malic acid, citricacid, isocitric acid, citramalic acid and tartronic acid.

From the standpoints of the compatibility with thermoplastic resins andthe antistatic properties, it is preferred that the polymer compound (E)have a structure in which a polyester (A), which is constituted by adiol and a dicarboxylic acid, the compound (B) and the polycarboxylicacid compound (D) are bound via ester bonds.

Further, from the standpoints of the compatibility with thermoplasticresins and the antistatic properties, it is also preferred that thepolymer compound (E) have a structure in which a block polymer (C)having hydroxyl groups at both ends and the above-describedpolycarboxylic acid compound (D) are bound via an ester bond, the blockpolymer (C) comprising a block constituted by the polyester (A), whichis constituted by a diol and a dicarboxylic acid, and a blockconstituted by the compound (B) that are repeatedly and alternatelybound via ester bonds.

The polyester (A) of the present invention may be any polyester as longas it is composed of a diol and a dicarboxylic acid, and it is preferredthat the polyester (A) have a structure in which a residue obtained byremoving a hydroxyl group from the diol and a residue obtained byremoving a carboxyl group from the dicarboxylic acid are bound via anester bond.

The polyester (A) preferably have a structure comprising carboxyl groupat one or both ends, and more preferably have a structure comprisingcarboxyl groups at both ends. Further, the polymerization degree of thepolyester (A) is preferably in a range of 2 to 50.

When the polyester (A) has a carboxyl group at one or both ends, it ispreferred that the structure of the polymer compound (E) be formed byforming an ester bond by reaction between the carboxyl group of thepolyester (A) and the hydroxyl group of the compound (B).

When the polyester (A) has hydroxyl groups at both ends, it is preferredthat the structure of the polymer compound (E) be formed by forming anester bond by reaction between the hydroxyl group of the polyester (A)and the carboxyl group of the compound (D).

The polyester (A) can be obtained by, for example, allowing theabove-described dicarboxylic acid to undergo a polycondensation reactionwith the above-described diol.

The dicarboxylic acid may be a derivative (such as an acid anhydride, analkyl ester, an alkali metal salt or an acid halide) of a dicarboxylicacid. In cases where the polyester (A) is obtained using such aderivative, the polyester (A) in this state may be directly subjected tothe subsequent reaction for obtaining the block polymer (C) having astructure comprising hydroxyl groups at both ends or subjected to thesubsequent reaction with polycarboxylic acid (D). Further, two or moredicarboxylic acids and derivatives thereof may be used in combination.

The polyester (A) having carboxyl groups at both ends can be obtainedby, for example, allowing the above-described dicarboxylic acid orderivative thereof to undergo a polycondensation reaction with theabove-described diol.

As for the reaction ratio of the dicarboxylic acid or derivative thereofwith respect to the diol in this case, it is preferred that thedicarboxylic acid or derivative thereof be used in an excess amount,preferably in an excess of 1 mole in terms of molar ratio with respectto the diol, such that the resulting polyester has carboxyl groups atboth ends.

The polyester (A) having a carboxyl group at one end can be obtained by,for example, allowing the above-described dicarboxylic acid orderivative thereof and the above-described diol to undergo apolycondensation reaction. In this case, as for the reaction ratiobetween the dicarboxylic acid or derivative thereof and the diol, it ispreferred that the dicarboxylic acid or derivative thereof and the diolbe used in equivalent amounts in terms of molar ratio such that one endof the resulting polyester is a carboxyl group.

The polyester (A) having hydroxyl groups at both ends can be obtainedby, for example, allowing the above-described dicarboxylic acid orderivative thereof and the above-described diol to undergo apolycondensation reaction. In this case, as for the reaction ratiobetween the dicarboxylic acid or derivative thereof and the diol, it ispreferred that the diol be used in an excess amount, particularly in anexcess of 1 mole in terms of molar ratio with respect to thedicarboxylic acid, such that the resulting polyester has hydroxyl groupsat both ends.

The polyester (A) may be a mixture of such polyesters.

In the polycondensation reaction, a catalyst which promotesesterification reaction may be used and, as such a catalyst, aconventionally known catalyst such as dibutyl tin oxide, tetraalkyltitanate, zirconium acetate or zinc acetate can be employed.

In cases where a derivative such as a carboxylic acid ester, metalcarboxylate or carboxylic acid halide is used in place of thedicarboxylic acid, after the derivative and the diol are allowed toreact with each other, both ends of the resultant may be treated to bedicarboxylic acids, or the resultant may be directly subjected to areaction for obtaining the block polymer (C) having a structurecomprising carboxyl groups at both ends.

A preferred polyester (A), which is composed of a diol and adicarboxylic acid and has carboxyl groups at both ends, may be anypolyester as long as it reacts with the component (B) to form an esterbond and thereby constitutes the structure of the block polymer (C), andthe carboxyl groups at both ends may be protected or modified, or may bein a precursor form. Further, in order to inhibit oxidation of theproduct during the reaction, an antioxidant such as a phenolicantioxidant may also be added to the reaction system.

The compound (B) having hydroxyl groups at both ends may be any compoundas long as it reacts with the component (A) to form an ester bond andthereby constitutes the structure of the block polymer (C). The hydroxylgroups at both ends may be protected or modified, or may be in aprecursor form.

The block polymer (C) according to the present invention, which has astructure comprising hydroxyl groups at both ends, contains a blockconstituted by the polyester (A) and a block constituted by the compound(B) and has a structure in which these blocks are repeatedly andalternately bound via ester bonds formed by carboxyl groups and hydroxylgroups. One example of the block polymer (C) is a block polymer having astructure represented by the following Formula (3):

In the Formula (3), (A) represents a block constituted by the polyester(A) having carboxyl groups at both ends; (B) represents a blockconstituted by the compound (B) having hydroxyl groups at both ends; andt represents the number of repeating units, which is preferably 1 to 10,more preferably 1 to 7, most preferably 1 to 5.

The block polymer (C) having a structure comprising hydroxyl groups atboth ends can be obtained by allowing the polyester (A) having carboxylgroups at both ends and the compound (B) having hydroxyl groups at bothends to undergo a polycondensation reaction; however, as long as theblock polymer (C) has a structure that is equivalent to the one in whichthe polyester (A) and the compound (B) are repeatedly and alternatelybound via ester bonds formed by carboxyl groups and hydroxyl groups, itis not necessarily required that the block polymer (C) be synthesizedfrom the polyester (A) and the compound (B).

As for the reaction ratio between the polyester (A) and the compound(B), by adjusting the amount of the compound (B) to be (X+1) mol withrespect to X mol of the polyester (A), the block polymer (C) havinghydroxyl groups at both ends can be preferably obtained.

As for the reaction, after the completion of the synthesis reaction ofthe polyester (A), without the thus synthesized polyester (A) beingisolated, the compound (B) may be added to the reaction system andallowed to react with the polyester (A) as is.

In the polycondensation reaction, a catalyst which promotesesterification reaction may be used and, as such a catalyst, aconventionally known catalyst such as dibutyl tin oxide, tetraalkyltitanate, zirconium acetate or zinc acetate can be employed. Further, inorder to inhibit oxidation of the product during the reaction, anantioxidant such as a phenolic antioxidant may also be added to thereaction system.

It is preferred that the polymer compound (E) according to the presentinvention have a structure in which the block polymer (C) having astructure comprising hydroxyl groups at both ends and the polycarboxylicacid compound (D) are bound via an ester bond formed by a terminalhydroxyl group of the block polymer (C) and a carboxyl group of thepolycarboxylic acid compound (D). The polymer compound (E) may furthercomprise an ester bond formed by a hydroxyl group of the polyester (A)and a carboxyl group of the polycarboxylic acid compound (D).

In order to obtain the polymer compound (E), the hydroxyl groups of theblock polymer (C) and the carboxyl groups of the polycarboxylic acidcompound (D) can be allowed to react with each other. The number of thecarboxyl groups of the polycarboxylic acid compound is preferably 0.5 to5 equivalents, more preferably 0.5 to 1.5 equivalents, with respect tothe number of the hydroxyl groups of the block polymer (C) to bereacted. Further, the reaction can be performed in a variety ofsolvents, or it may be performed in a molten state.

The amount of the polycarboxylic acid compound (D) to be used in thereaction is preferably 0.1 to 2.0 equivalents, more preferably 0.2 to1.5 equivalents, with respect to the number of the hydroxyl groups ofthe block polymer (C) to be reacted.

As for the reaction, after the completion of the synthesis reaction ofthe block polymer (C), without the thus synthesized block polymer (C)being isolated, the polycarboxylic acid compound (D) may be added to thereaction system and allowed to react with the block polymer (C) as is.In this case, unreacted hydroxyl groups of the polyester (A) used in anexcess amount in the synthesis of the block polymer (C) may react withsome of the carboxyl groups of the polycarboxylic acid compound (D) toform ester bonds.

It is not necessarily required that a preferred polymer compound (E) ofthe present invention be synthesized from the block polymer (C) and thepolycarboxylic acid compound (D), as long as the polymer compound (E)has a structure that is equivalent to the one in which the block polymer(C) having a structure comprising hydroxyl groups at both ends and thepolycarboxylic acid compound (D) are bound via an ester bond formed by ahydroxyl group of the block polymer (C) and a carboxyl group of thepolycarboxylic acid compound (D).

In the polymer compound (E) of the present invention, the blockconstituted by the polyester (A) has a number-average molecular weightof preferably 800 to 8,000, more preferably 1,000 to 6,000, still morepreferably 2,000 to 4,000, in terms of polystyrene. In the polymercompound (E), the block constituted by the compound (B) having hydroxylgroups at both ends has a number-average molecular weight of preferably400 to 6,000, more preferably 1,000 to 5,000, still more preferably2,000 to 4,000, in terms of polystyrene. Further, in the polymercompound (E), the block constituted by the block polymer (C) having astructure comprising hydroxyl groups at both ends has a number-averagemolecular weight of preferably 5,000 to 25,000, more preferably 7,000 to17,000, still more preferably 9,000 to 13,000, in terms of polystyrene.

It is also preferred that at least one selected from the groupconsisting of alkali metal salts and Group II metal salts be furtherincorporated into the antistatic agent of the present invention toobtain an antistatic agent composition.

Examples of the alkali metal salts and Group II element salts includethose of organic acids and inorganic acids. Examples of the alkali metalinclude lithium, sodium, potassium, cesium and rubidium, and examples ofthe Group II element include beryllium, magnesium, calcium, strontiumand barium. Further, examples of the organic acids include aliphaticmonocarboxylic acids having 1 to 18 carbon atoms, such as formic acid,acetic acid, propionic acid, butyric acid and lactic acid; aliphaticdicarboxylic acids having 1 to 12 carbon atoms, such as oxalic acid,malonic acid, succinic acid, fumaric acid, maleic acid and adipic acid;aromatic carboxylic acids, such as benzoic acid, phthalic acid,isophthalic acid, terephthalic acid and salicylic acid; and sulfonicacids having 1 to 20 carbon atoms, such as methanesulfonic acid,p-toluenesulfonic acid, dodecylbenzenesulfonic acid andtrifluoromethanesulfonic acid, and examples of the inorganic acidsinclude hydrochloric acid, hydrobromic acid, sulfuric acid, sulfurousacid, phosphoric acid, phosphorous acid, polyphosphoric acid, nitricacid and perchloric acid. Thereamong, from the standpoint of antistaticproperties, alkali metal salts are preferred, salts of lithium, sodiumand potassium are more preferred, and salts of lithium are mostpreferred. Further, from the standpoint of antistatic properties,acetates, perchlorates, p-toluenesulfonates and dodecylbenzenesulfonatesare preferred.

Specific examples of the alkali metal salts and Group II element saltsinclude lithium acetate, sodium acetate, potassium acetate, lithiumchloride, sodium chloride, potassium chloride, magnesium chloride,calcium chloride, lithium phosphate, sodium phosphate, potassiumphosphate, lithium sulfate, sodium sulfate, magnesium sulfate, calciumsulfate, lithium perchlorate, sodium perchlorate, potassium perchlorate,lithium p-toluenesulfonate, sodium p-toluenesulfonate, potassiump-toluenesulfonate, lithium dodecylbenzenesulfonate, sodiumdodecylbenzenesulfonate and potassium dodecylbenzenesulfonate.Thereamong, for example, lithium acetate, potassium acetate, lithiump-toluenesulfonate, sodium p-toluenesulfonate and lithium chloride arepreferred.

The above-described alkali metal salt(s) and/or Group II element salt(s)may be incorporated into the polymer compound (E) used in the antistaticagent of the present invention, or may be incorporated into athermoplastic resin along with the polymer compound (E). The amount ofthe alkali metal salt(s) and/or Group II metal salt(s) to beincorporated is preferably 0.01 to 20 parts by mass, more preferably 0.1to 15 parts by mass, most preferably 1 to 10 parts by mass, with respectto 100 parts by mass of the polymer compound (E).

Further, a surfactant may also be incorporated into the antistatic agentof the present invention to use the resultant as an antistatic agentcomposition. As the surfactant, a nonionic, anionic, cationic oramphoteric surfactant can be employed. Examples of the nonionicsurfactant include polyethylene glycol-type nonionic surfactants, suchas higher alcohol ethylene oxide adducts, fatty acid ethylene oxideadducts, higher alkylamine ethylene oxide adducts and polypropyleneglycol ethylene oxide adducts; and polyhydric alcohol-type nonionicsurfactants, such as polyethylene oxides, glycerin fatty acid esters,pentaerythritol fatty acid esters, fatty acid esters of sorbitol orsorbitan, polyhydric alcohol alkyl ethers and alkanolamine aliphaticamides, and examples of the anionic surfactant include carboxylates suchas alkali metal salts of higher fatty acids; sulfates such as higheralcohol sulfates and higher alkyl ether sulfates; sulfonates such asalkylbenzenesulfonates, alkylsulfonates and paraffin sulfonates; andphosphates such as higher alcohol phosphates. Examples of the cationicsurfactant include quaternary ammonium salts such asalkyltrimethylammonium salts, and examples of the amphoteric surfactantinclude amino acid-type amphoteric surfactants such as higheralkylaminopropionates; and betaine-type amphoteric surfactants such ashigher alkyl dimethylbetaines and higher alkyl dihydroxyethylbetaines.These surfactants may be used individually, or two or more thereof maybe used in combination. In the present invention, among theabove-described surfactants, anionic surfactants are preferred, andsulfonates such as alkylbenzenesulfonates, alkylsulfonates and paraffinsulfonates are particularly preferred.

The surfactant(s) may be incorporated into the polymer compound (E) usedin the antistatic agent of the present invention, or may be incorporatedinto a thermoplastic resin along with the polymer compound (E). Theamount of the surfactant(s) to be incorporated is preferably 0.01 to 20parts by mass, more preferably 0.1 to 15 parts by mass, most preferably1 to 10 parts by mass, with respect to 100 parts by mass of the polymercompound (E).

Further, a polymer-type antistatic agent may also be incorporated intothe antistatic agent of the present invention to use the resultant as anantistatic agent composition. As the polymer-type antistatic agent, forexample, a known polymer-type antistatic agent such as a polyether esteramide can be used, and examples thereof include the polyether esteramide disclosed in Japanese Unexamined Patent Application PublicationNo. H7-10989 which comprises a polyoxyalkylene adduct of bisphenol A.Further, a block polymer having 2 to 50 repeating structures eachcomposed of a polyolefin block and a hydrophilic polymer block can alsobe used, and examples thereof include the block polymer disclosed in thespecification of U.S. Pat. No. 6,552,131.

The polymer-type antistatic agent may be incorporated into the polymercompound (E) used in the antistatic agent of the present invention, orit may be incorporated in a thermoplastic resin along with the polymercompound (E). The amount of the polymer-type antistatic agent to beincorporated is preferably 0 to 50 parts by mass, more preferably 5 to20 parts by mass, with respect to 100 parts by mass of the polymercompound (E).

Still further, the antistatic agent of the present invention may also beblended with an ionic liquid to use the resultant as an antistatic agentcomposition. The ionic liquid is, for example, a normaltemperature-molten salt having a melting point of not higher than roomtemperature and an initial electrical conductivity of 1 to 200 ms/cm,preferably 10 to 200 ms/cm, in which at least one cation or anionconstituting the ionic liquid is an organic ion. Examples of such anormal temperature-molten salt include the one disclosed in WO 95/15572.

The cation constituting the ionic liquid is, for example, one selectedfrom the group consisting of amidinium, pyridinium, pyrazolium andguanidinium cations.

Thereamong, examples of the amidinium cation include the followings:

(1) imidazolinium cations

those having 5 to 15 carbon atoms, such as1,2,3,4-tetramethylimidazolinium and 1,3-dimethylimidazolinium;

(2) imidazolium cations

those having 5 to 15 carbon atoms, such as 1,3-dimethylimidazolium and1-ethyl-3-methylimidazolium;

(3) tetrahydropyrimidinium cations

those having 6 to 15 carbon atoms, such as1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium and1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium; and

(4) dihydropyrimidinium cations

those having 6 to 20 carbon atoms, such as1,3-dimethyl-1,4-dihydropyrimidinium,1,3-dimethyl-1,6-dihydropyrimidinium,8-methyl-1,8-diazabicyclo[5,4,0]-7,9-undecadienium and8-methyl-1,8-diazabicyclo[5,4,0]-7,10-undecadienium.

Examples of the pyridinium cation include those having 6 to 20 carbonatoms, such as 3-methyl-1-propylpyridinium and1-butyl-3,4-dimethylpyridinium.

Examples of the pyrazolium cation include those having 5 to 15 carbonatoms, such as 1,2-dimethylpyrazolium and 1-n-butyl-2-methylpyrazolium.

Examples of the guanidinium cation include the followings:

(1) guanidinium cations having an imidazolinium skeleton

those having 8 to 15 carbon atoms, such as2-dimethylamino-1,3,4-trimethylimidazolinium and2-diethylamino-1,3,4-trimethylimidazolinium;

(2) guanidinium cations having an imidazolium skeleton

those having 8 to 15 carbon atoms, such as2-dimethylamino-1,3,4-trimethylimidazolium and2-diethylamino-1,3,4-trimethylimidazolium;

(3) guanidinium cations having a tetrahydropyrimidinium skeleton

those having 10 to 20 carbon atoms, such as2-dimethylamino-1,3,4-trimethyl-1,4,5,6-tetrahydropyrimidinium and2-diethylamino-1,3-dimethyl-4-ethyl-1,4,5,6-tetrahydropyrimidinium; and

(4) guanidinium cations having a dihydropyrimidinium skeleton

those having 10 to 20 carbon atoms, such as2-dimethylamino-1,3,4-trimethyl-1,4-dihydropyrimidinium,2-dimethylamino-1,3,4-trimethyl-1,6-dihydropyrimidinium,2-diethylamino-1,3-dimethyl-4-ethyl-1,4-dihydropyrimidinium and2-diethylamino-1,3-dimethyl-4-ethyl-1,6-dihydropyrimidinium.

The above-described cations may be used individually, or two or morethereof may be used in combination. Thereamong, from the standpoint ofantistatic properties, amidinium cations are preferred, imidazoliumcations are more preferred, and 1-ethyl-3-methylimidazolium cation isparticularly preferred.

In the ionic liquid, examples of the organic or inorganic acidconstituting the anion include the followings. Examples of the organicacid include carboxylic acid, sulfuric acid ester, sulfonic acid andphosphoric acid ester, and examples of the inorganic acid includesuperacids (such as fluoroboric acid, tetrafluoroboric acid, perchloricacid, hexafluorophosphoric acid, hexafluoroantimonic acid andhexafluoroarsenic acid), phosphoric acid and boric acid. These organicand inorganic acids may be used individually, or two or more thereof maybe used in combination.

Among these organic and inorganic acids, from the standpoint of theantistatic properties of the ionic liquid, acids forming a conjugatebase of superacid or an anion other than a conjugate base of super acid,which allow the anion constituting the ionic liquid to have a Hammettacidity function (−H₀) of 12 to 100, and mixtures of such acids arepreferred.

Examples of the anion other than a conjugate base of superacid includehalogen (such as fluorine, chlorine and bromine) ions, alkyl (C1-12)benzenesulfonic acid (such as p-toluenesulfonic acid anddodecylbenzenesulfonic acid) ions, and poly (n=1 to 25)fluoroalkanesulfonic acid (such as undecafluoropentanesulfonic acid)ions.

Examples of the superacid include those derived from a protonic acid ora combination of a protonic acid and a Lewis acid, and mixtures thereof.Examples of the protonic acid used as the superacid includebis(trifluoromethylsulfonyl)imidic acid,bis(pentafluoroethylsulfonyl)imidic acid,tris(trifluoromethylsulfonyl)methane, perchloric acid, fluorosulfonicacid, alkane (C1 to C30) sulfonic acids (such as methanesulfonic acidand dodecanesulfonic acid), poly (n=1 to 30) fluoroalkane (C1 to C30)sulfonic acid (such as trifluoromethanesulfonic acid,pentafluoroethanesulfonic acid, heptafluoropropanesulfonic acid,nonafluorobutanesulfonic acid, undecafluoropentanesulfonic acid andtridecafluorohexanesulfonic acid), fluoroboric acid and tetrafluoroboricacid. Thereamong, from the standpoint of the ease of synthesis,fluoroboric acid, trifluoromethanesulfonic acid,bis(trifluoromethanesulfonyl)imidic acid andbis(pentafluoroethylsulfonyl)imidic acid are preferred.

Examples of the protonic acid used in combination with a Lewis acidinclude hydrogen halides (such as hydrogen fluoride, hydrogen chloride,hydrogen bromide and hydrogen iodide), perchloric acid, fluorosulfonicacid, methanesulfonic acid, trifluoromethanesulfonic acid,pentafluoroethanesulfonic acid, nonafluorobutanesulfonic acid,undecafluoropentanesulfonic acid, tridecafluorohexanesulfonic acid, andmixtures thereof. Thereamong, from the standpoint of the initialelectrical conductivity of the ionic liquid, hydrogen fluoride ispreferred.

Examples of the Lewis acid include boron trifluoride, phosphoruspentafluoride, antimony pentafluoride, arsenic pentafluoride, tantalumpentafluoride, and mixtures thereof. Thereamong, from the standpoint ofthe initial electrical conductivity of the ionic liquid, borontrifluoride and phosphorus pentafluoride are preferred.

The combination of a protonic acid and a Lewis acid may be anycombination, and examples of a superacid derived therefrom includetetrafluoroboric acid, hexafluorophosphoric acid, hexafluorotantalicacid, hexafluoroantimonic acid, hexafluorotantalum sulfonic acid,tetrafluoroboric acid, hexafluorophosphoric acid, chlorotrifluoroboricacid, hexafluoroarsenic acid, and mixtures thereof.

Among the above-described anions, from the standpoint of the antistaticproperties of the ionic liquid, conjugate bases of superacids(superacids derived from a protonic acid and superacids derived from acombination of a protonic acid and a Lewis acid) are preferred, andsuperacids derived from a protonic acid and conjugate bases ofsuperacids derived from a protonic acid, boron trifluoride and/orphosphorus pentafluoride are more preferred.

Among the above-described ionic liquids, from the standpoint of theantistatic properties, amidinium cation-containing ionic liquids arepreferred, 1-ethyl-3-methylimidazolium cation-containing ionic liquidsare more preferred, and1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide isparticularly preferred.

The amount of the ionic liquid to be blended is preferably 0.01 to 20parts by mass, more preferably 0.1 to 15 parts by mass, most preferably1 to 10 parts by mass, with respect to 100 parts by mass of the polymercompound (E).

Yet still further, a compatibilizer may also be incorporated into theantistatic agent of the present invention to use the resultant as anantistatic agent composition. By incorporating a compatibilizer, thecompatibility of the antistatic agent component with other componentsand a thermoplastic resin can be improved. Examples of such acompatibilizer include modified vinyl polymers having at least onefunctional group (polar group) selected from the group consisting of acarboxyl group, an epoxy group, an amino group, a hydroxyl group and apolyoxyalkylene group, such as the polymer disclosed in JapaneseUnexamined Patent Application Publication No. H3-258850, the sulfonylgroup-containing modified vinyl polymer disclosed in Japanese UnexaminedPatent Application Publication No. H6-345927 and block polymerscomprising a polyolefin moiety and an aromatic vinyl polymer moiety.

The compatibilizer may be incorporated into the polymer compound (E)used in the antistatic agent of the present invention, or it may beincorporated into a thermoplastic resin along with the polymer compound(E). The amount of the compatibilizer to be incorporated is preferably0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, withrespect to 100 parts by mass of the polymer compound (E).

The antistatic agent of the present invention and the antistatic agentcomposition of the present invention can each be particularly preferablyincorporated into a thermoplastic resin to use the resultant as anantistatic resin composition. Examples of the thermoplastic resininclude α-olefin polymers such as polypropylene, high-densitypolyethylene, low-density polyethylene, linear low-density polyethylene,cross-linked polyethylene, ultrahigh-molecular-weight polyethylene,polybutene-1, poly-3-methylpentene and poly-4-methylpentene;polyolefin-based resins and copolymers thereof, such as ethylene-vinylacetate copolymers, ethylene-ethyl acrylate copolymers andethylene-propylene copolymers; halogen-containing resins, such aspolyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene,chlorinated polypropylene, polyvinylidene fluoride, chlorinated rubbers,vinyl chloride-vinyl acetate copolymers, vinyl chloride-ethylenecopolymers, vinyl chloride-vinylidene chloride copolymers, vinylchloride-vinylidene chloride-vinyl acetate ternary copolymers, vinylchloride-acrylate copolymers, vinyl chloride-maleate copolymers andvinyl chloride-cyclohexylmaleimide copolymers; petroleum resins;coumarone resins; polystyrene; polyvinyl acetate; acrylic resins;copolymers (e.g., AS resins, ABS (Acrylonitrile-Butadiene-Stylenecopolymer) resins, ACS resins, SBS resins, MBS resins and heat-resistantABS resins) composed of styrene and/or α-methylstyrene with othermonomer (e.g., maleic anhydride, phenylmaleimide, methyl methacrylate,butadiene or acrylonitrile); polymethyl methacrylates; polyvinylalcohols; polyvinyl formals; polyvinyl butyrals; aromatic polyestersincluding polyalkylene terephthalates, such as polyethyleneterephthalate, polybutylene terephthalate and polycyclohexanedimethylene terephthalate, and polyalkylene naphthalates such aspolyethylene naphthalate and polybutylene naphthalate, and linearpolyesters such as polytetramethylene terephthalate; degradablealiphatic polyesters such as polyhydroxy butyrate, polycaprolactone,polybutylene succinate, polyethylene succinate, polylactic acid,polymalic acid, polyglycolic acid, polydioxane and poly(2-oxetanone);and thermoplastic resins and blends thereof, such as polyamides (e.g.,polyphenylene oxide, polycaprolactam and polyhexamethylene adipamide),polycarbonates, polycarbonate/ABS resins, branched polycarbonates,polyacetals, polyphenylene sulfides, polyurethanes, cellulose-basedresins, polyimide resins, polysulfones, polyphenylene ethers, polyetherketones, polyether ether ketones and liquid crystal polymers. Further,the thermoplastic resin may be an elastomer, such as an isoprene rubber,a butadiene rubber, an acrylonitrile-butadiene copolymer rubber, astyrene-butadiene copolymer rubber, a fluorine rubber, a siliconerubber, an olefin-based elastomer, a styrene-based elastomer, apolyester-based elastomer, a nitrile-based elastomer, a nylon-basedelastomer, a vinyl chloride-based elastomer, a polyamide-based elastomeror a polyurethane-based elastomer. In the present invention, thesethermoplastic resins may be used individually, or two or more thereofmay be used in combination. Moreover, these thermoplastic resins may bealloyed as well.

These thermoplastic resins can be used regardless of molecular weight,polymerization degree, density, softening point, ratio ofsolvent-insoluble component(s), degree of stereoregularity, presence orabsence of catalyst residue, type and blend ratio of each materialmonomer, type of polymerization catalyst (e.g., a Ziegler catalyst or ametallocene catalyst). Among the above-described thermoplastic resins,from the standpoint of the antistatic properties, one or more selectedfrom the group consisting of polyolefin-based resins, polystyrene-basedresins and copolymers thereof are preferably used.

In the antistatic resin composition of the present invention, the massratio of the thermoplastic resin(s) and the antistatic agent or theantistatic agent composition is preferably in a range of 99/1 to 40/60.

The method of incorporating the polymer compound (E) into athermoplastic resin is not particularly restricted, and any commonlyused method can be employed. For example, the polymer compound (E) canbe mixed and kneaded into the thermoplastic resin by roll kneading orbumper kneading, or using an extruder or a kneader. Further, the polymercompound (E) may be directly added to the thermoplastic resin; however,as required, the polymer compound (E) may be impregnated into a carrierbefore the addition. In order to impregnate the polymer compound (E)into a carrier, the polymer compound (E) and the carrier can be directlyheat-mixed, or a method in which the polymer compound (E) is dilutedwith an organic solvent before being impregnated into the carrier andthe solvent is subsequently removed can be employed as required. As thecarrier, one which is known as a filler or bulking agent of a syntheticresin, or a flame retardant or light stabilizer that is solid at normaltemperature can be employed, and examples of such a carrier includecalcium silicate powder, silica powder, talc powder, alumina powder,titanium oxide powder, and these carriers having chemically modifiedsurface, as well as the below-described flame retardants andantioxidants that are solid. Thereamong, those carriers havingchemically modified surface are preferred, and silica powder havingchemically modified surface is more preferred. These carriers have anaverage particle size of preferably 0.1 to 100 μm, more preferably 0.5to 50 μm.

As the method of incorporating the polymer compound (E) into athermoplastic resin, the polymer compound (E) may be synthesized bykneading the block polymer (C) and the polycarboxylic acid compound (D)simultaneously with the thermoplastic resin. Alternatively, the polymercompound (E) may be incorporated using a method of obtaining a moldedarticle by mixing the polymer compound (E) and the thermoplastic resinat the time of molding such as injection molding, or a masterbatch ofthe polymer compound (E) and the thermoplastic resin, which has beenproduced in advance, may be incorporated.

To the antistatic resin composition of the present invention, asrequired, a variety of additives such as a phenolic antioxidant, aphosphorus-based antioxidant, a thioether-based antioxidant, anultraviolet absorber and a hindered amine-based light stabilizer mayalso be added. By this, the resin composition of the present inventioncan be stabilized.

Examples of the phenolic antioxidants include2,6-di-tert-butyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol,distearyl(3,5-di-tert-butyl-4-hydroxybenzyl)phosphonate,1,6-hexamethylene-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acidamide], 4,4′-thiobis(6-tert-butyl-m-cresol),2,2′-methylene-bis(4-methyl-6-tert-butylphenol),2,2′-methylene-bis(4-ethyl-6-tert-butylphenol),4,4′-butylidene-bis(6-tert-butyl-m-cresol),2,2′-ethylidene-bis(4,6-di-tert-butylphenol),2,2′-ethylidene-bis(4-sec-butyl-6-tert-butylphenol),1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanurate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5-methylbenzyl)phenol,stearyl(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acidmethyl]methane, thiodiethyleneglycol-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],1,6-hexamethylene-bis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butyric acid]glycol ester,bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl]terephthalate,1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate,3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane,and triethyleneglycol-bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]. Thesephenolic antioxidants are added in an amount of preferably 0.001 to 10parts by mass, more preferably 0.05 to 5 parts by mass, with respect to100 parts by mass of the thermoplastic resin.

Examples of the phosphorus-based antioxidants include trisnonylphenylphosphite,tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite,tridecyl phosphite, octyldiphenyl phosphite, di(decyl)monophenylphosphite, di(tridecyl)pentaerythritol diphosphite,di(nonylphenyl)pentaerythritol diphosphite,bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite,bis(2,4-dicumylphenyl)pentaerythritol diphosphite,tetra(tridecyl)isopropylidenediphenol diphosphite,tetra(tridecyl)-4,4′-n-butylidene-bis(2-tert-butyl-5-methylphenol)diphosphite,hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butanetriphosphite, tetrakis(2,4-di-tert-butylphenyl)biphenylenediphosphonite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide,2,2′-methylene-bis(4,6-tert-butylphenyl)-2-ethylhexyl phosphite,2,2′-methylene-bis(4,6-tert-butylphenyl)-octadecyl phosphite,2,2′-ethylidene-bis(4,6-di-tert-butylphenyl)fluorophosphite,tris(2-[(2,4,8,10-tetrakis-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine,and phosphite of 2-ethyl-2-butylpropylene glycol and2,4,6-tri-tert-butylphenol. These phosphorus-based antioxidants areadded in an amount of preferably 0.001 to 10 parts by mass, morepreferably 0.05 to 5 parts by mass, with respect to 100 parts by mass ofthe thermoplastic resin.

Examples of the thioether-based antioxidants include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristylthiodipropionate and distearyl thiodipropionate; andpentaerythritol-tetra(β-alkylthiopropionic acid)esters. Thesethioether-based antioxidants are added in an amount of preferably 0.001to 10 parts by mass, more preferably 0.05 to 5 parts by mass, withrespect to 100 parts by mass of the thermoplastic resin.

Examples of the ultraviolet absorbers include 2-hydroxybenzophenonessuch as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-octoxybenzophenone and5,5′-methylene-bis(2-hydroxy-4-methoxybenzophenone);2-(2′-hydroxyphenyl)benzotriazoles such as2-(2′-hydroxy-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-3′,5′-di-tert-butylphenyl)-5-chlorobenzotriazole,2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole,2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole,2-(2′-hydroxy-3′,5′-dicumylphenyl)benzotriazole,2,2′-methylene-bis(4-tert-octyl-6-(benzotriazolyl)phenol) and2-(2′-hydroxy-3′-tert-butyl-5′-carboxyphenyl)benzotriazole; benzoatessuch as phenyl salicylate, resorcinol monobenzoate,2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate,2,4-di-tert-amylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate andhexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; substituted oxanilidessuch as 2-ethyl-2′-ethoxyoxanilide and 2-ethoxy-4′-dodecyloxanilide;cyanoacrylates such as ethyl-α-cyano-β,β-diphenyl acrylate andmethyl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; and triaryltriazines such as2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine,2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine and2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine.These ultraviolet absorbers are added in an amount of preferably 0.001to 30 parts by mass, more preferably 0.05 to 10 parts by mass, withrespect to 100 parts by mass of the thermoplastic resin.

Examples of the hindered amine-based light stabilizers include hinderedamine compounds such as 2,2,6,6-tetramethyl-4-piperidyl stearate,1,2,2,6,6-pentamethyl-4-piperidyl stearate,2,2,6,6-tetramethyl-4-piperidyl benzoate,bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(1,2,2,6,6-tetramethyl-4-piperidyl)sebacate,bis(1-oxtoxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate,bis(2,2,6,6-tetramethyl-4-piperidyl).di(tridecyl)-1,2,3,4-butanetetracarboxylate,bis(1,2,2,6,6-pentamethyl-4-piperidyl).di(tridecyl)-1,2,3,4-butanetetracarboxylate,bis(1,2,2,4,4-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol/diethyl succinatepolycondensate,1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-morpholino-s-triazinepolycondensate,1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-tert-octylamino-s-triazinepolycondensate,1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazine-6-yl]-1,5,8,12-tetraazadodecane,1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazine-6-yl]-1,5,8,12-tetraazadodecane,1,6,11-tris[2,4-bis(N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazine-6-yl]aminoundecane and1,6,11-tris[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazine-6-yl]aminoundecane. These hindered amine-based light stabilizers are added in anamount of preferably 0.001 to 30 parts by mass, more preferably 0.05 to10 parts by mass, with respect to 100 parts by mass of the thermoplasticresin.

In cases where a polyolefin-based resin is used as the thermoplasticresin, in order to neutralize residual catalyst in the polyolefin resin,it is preferred to further add a known neutralizer as required. Examplesof the neutralizer include fatty acid metal salts such as calciumstearate, lithium stearate and sodium stearate; and fatty acid amidecompounds such as ethylene-bis(stearamide),ethylene-bis(12-hydroxystearamide) and stearic acid amide, and theseneutralizers may be used in combination.

Further, to the antistatic resin composition of the present invention,as required, for example, a nucleating agent (e.g., an aromatic metalcarboxylate, an alicyclic metal alkylcarboxylate, aluminump-tert-butylbenzoate, an aromatic metal phosphate or a kind ofdibenzylidene sorbitol), a metallic soap, a hydrotalcite, a triazinering-containing compound, a metal hydroxide, a phosphoric acidester-based flame retardant, a condensed phosphoric acid ester-basedflame retardant, a phosphate-based flame retardant, an inorganicphosphorus-based flame retardant, a (poly)phosphate-based flameretardant, a halogen-based flame retardant, a silicon-based flameretardant, an antimony oxide such as antimony trioxide, other inorganicflame retardant aid, other organic flame retardant aid, a filler, apigment, a lubricant, and/or a foaming agent, may also be added.

Examples of the triazine ring-containing compounds include melamine,ammeline, benzoguanamine, acetoguanamine, phthalodiguanamine, melaminecyanurate, melamine pyrophosphate, butylene diguanamine, norbornenediguanamine, methylene diguanamine, ethylene dimelamine, trimethylenedimelamine, tetramethylene dimelamine, hexamethylene dimelamine and1,3-hexylene dimelamine.

Examples of the metal hydroxides include magnesium hydroxide, aluminumhydroxide, calcium hydroxide, barium hydroxide, zinc hydroxide andKISUMA 5A (magnesium hydroxide, manufactured by Kyowa Chemical IndustryCo., Ltd.).

Examples of the phosphate-based flame retardants include trimethylphosphate, triethyl phosphate, tributyl phosphate, tributoxyethylphosphate, trischloroethyl phosphate, trisdichloropropyl phosphate,triphenyl phosphate, tricresyl phosphate, cresyldiphenyl phosphate,trixylenyl phosphate, octyldiphenyl phosphate, xylenyldiphenylphosphate, tris(isopropylphenyl) phosphate, 2-ethylhexyldiphenylphosphate, t-butylphenyldiphenyl phosphate, bis(t-butylphenyl)phenylphosphate, tris(t-butylphenyl)phosphate, isopropylphenyldiphenylphosphate, bis(isopropylphenyl)diphenyl phosphate andtris(isopropylphenyl)phosphate.

Examples of the condensed phosphoric acid ester-based flame retardantsinclude 1,3-phenylene-bis(diphenylphosphate),1,3-phenylene-bis(dixylenylphosphate) and bisphenolA-bis(diphenylphosphate).

Examples of the (poly)phosphate-based flame retardants include ammoniumsalts and amine salts of (poly)phosphoric acid, such as ammoniumpolyphosphate, melamine polyphosphate, piperazine polyphosphate,melamine pyrophosphate and piperazine pyrophosphate.

Examples of the other inorganic flame retardant aids include inorganiccompounds such as titanium oxide, aluminum oxide, magnesium oxide,hydrotalcites, talc and montmorillonite, and surface-treated productsthereof. For example, a variety of commercially available products, suchas TIPAQUE R-680 (titanium oxide: manufactured by Ishihara SangyoKaisha, Ltd.), KYOWAMAG 150 (magnesium oxide: manufactured by KyowaChemical Industry Co., Ltd.), DHT-4A (hydrotalcite: manufactured byKyowa Chemical Industry Co., Ltd.) and ALCAMIZER 4 (zinc-modifiedhydrotalcite: manufactured by Kyowa Chemical Industry Co., Ltd.), can beused. Examples of the other organic flame retardant aids includepentaerythritol.

In addition, in the antistatic resin composition of the presentinvention, as required, an additive(s) normally used in syntheticresins, for example, a cross-linking agent, an anti-fogging agent, ananti-plate-out agent, a surface treatment agent, a plasticizer, alubricant, a flame retardant, a fluorescent agent, an antifungal agent,an antibacterial agent, a foaming agent, a metal inactivator, amold-release agent, a pigment, a processing aid, an antioxidant and/or alight stabilizer, may also be incorporated in such a range that does notimpair the effects of the present invention.

The additives to be incorporated into the antistatic resin compositionof the present invention may be directly added to a thermoplastic resin,or they may be incorporated into the antistatic agent or antistaticagent composition of the present invention, which may then be added to athermoplastic resin.

An antistatic resin molded article can be obtained by molding theantistatic resin composition of the present invention. The moldingmethod is not particularly restricted, and examples thereof includeextrusion processing, calender processing, injection molding, rolling,compression molding, blow molding and rotational molding. Moldedarticles of various shapes, such as resin plates, sheets, films,bottles, fibers and special shape articles, can be produced by thesemethods. Such molded articles obtained from the antistatic resincomposition of the present invention exhibit excellent antistaticperformance with excellent persistence. Further, the molded articlesalso have wiping resistance.

The antistatic resin composition of the present invention and moldedarticles thereof can be used in a wide range of industrial fields,including the fields of electricity/electronics/communication,agriculture/forestry/fisheries, mining, construction, foods, fibers,clothings, health care, coal, petroleum, rubbers, leathers, automobiles,precision instruments, wood materials, building materials, civilengineering, furnitures, printing and musical instruments.

More specific examples of applications where the antistatic resincomposition of the present invention and molded articles thereof can beused in office work automation equipments, such as printers, personalcomputers, word processors, keyboards, PDA (Personal Digital Assistant)devices, phones, copy machines, facsimiles, ECRs (electronic cashregisters), electronic calculators, electronic organizers, cards,holders and stationeries; household electric appliances, such as laundrymachines, refrigerators, vacuum cleaners, microwave ovens, lightingequipments, game machines, irons and kotatsu; audio and visual devices,such as televisions, video tape recorders, video cameras, radio-cassetteplayers, tape recorders, mini discs, CD players, speakers and liquidcrystal displays; and electric/electronic components and communicationdevices, such as connectors, relays, capacitors, switches, printedcircuit boards, coil bobbins, semiconductor sealing materials, LEDsealing materials, electric wires, cables, transformers, deflectionyokes, distribution boards and clocks; automobile interior and exteriormaterials; platemaking films; adhesive films; bottles; food containers;food packaging films; pharmaceutical and medical wrapping films; productpackaging films; agricultural films; agricultural sheets; and greenhousefilms.

Moreover, the antistatic resin composition of the present invention andmolded articles thereof can also be used in other various applications,including materials of cars, vehicles, ships, airplanes, buildings andhouses as well as construction and civil engineering materials, such asseats (e.g., stuffing and cover materials), belts, ceiling covers,convertible tops, armrests, door trims, rear package trays, carpets,mats, sun visors, wheel covers, mattress covers, air-bags, insulatingmaterials, straps, strap belts, wire coating materials, electricinsulating materials, paints, coating materials, veneer materials, floormaterials, baffle walls, wallpapers, wall decorating materials, exteriormaterials, interior materials, roof materials, deck materials, wallmaterials, pillar materials, floor boards, fence materials, framing andmoulding materials, window and door-shaping materials, shingle boards,sidings, terraces, balconies, soundproof boards, heat insulating boardsand window materials; and household articles and sporting goods, such asclothing materials, curtains, sheets, non-woven fabric, plywood boards,synthetic fiber boards, rugs, doormats, leisure sheets, buckets, hoses,containers, eye glasses, bags, casings, goggles, ski boards, rackets,terts and musical instruments.

EXAMPLES

The present invention will now be described concretely by way ofexamples thereof. It is noted here that, in the below-described examplesand the like, “%” and “ppm” are all based on mass unless otherwisespecified.

Antistatic agents were produced in accordance with the below-describedProduction Examples. Further, in the Production Examples, thenumber-average molecular weight was determined by the below-describedmethod of measuring the molecular weight.

<Method of Measuring Molecular Weight>

The number-average molecular weight (hereinafter, referred to as “Mn”)was measured by gel permeation chromatography (GPC). The conditions ofthe Mn measurement were as follows.

Apparatus: GPC apparatus, manufactured by JASCO Corporation

Solvent: tetrahydrofuran

Standard substance: polystyrene

Detector: differential refractometer (RI detector)

Column stationary phase: SHODEX KF-804L, manufactured by Showa DenkoK.K.

Column temperature: 40° C.

Sample concentration: 1 mg/1 mL

Flow rate: 0.8 mL/min

Injection volume: 100 μL

Production Example 1

To a separable flask, 228 g of 1,4-cyclohexane dimethanol, 230 g ofadipic acid and 0.4 g of an antioxidant (ADK STAB AO-60) were added, andthese materials were allowed to polymerize for 4 hours under normalpressure with the temperature being slowly increased from 160° C. to200° C. Then, 0.2 g of zirconium acetate was added thereto and allowedto polymerize for 3 hours at 200° C. under reduced pressure, whereby apolyester was obtained. This polyester had an acid value of 14 and anumber-average molecular weight (Mn) of 5,200 in terms of polystyrene.

Next, 300 g of the thus obtained polyester, 150 g of polyethylene glycolhaving a number-average molecular weight of 4,000, 0.45 g of anantioxidant (ADK STAB AO-60) and 0.45 g of zirconium acetate were addedand allowed to polymerize at 200° C. for 5 hours under reduced pressure,whereby a polyether ester comprising hydroxyl groups at both ends wasobtained. This polyether ester had a hydroxyl value of 9 and anumber-average molecular weight (Mn) of 12,200 in terms of polystyrene.

To 200 g of the thus obtained block polymer comprising hydroxyl groupsat both ends, 3.6 g of pyromellitic anhydride was added as apolycarboxylic acid, and the resulting mixture was allowed to polymerizeat 240° C. for 4 hours under reduced pressure, whereby an antistaticagent (E)-1 according to the present invention was obtained.

Production Example 2

To a separable flask, 228 g of 1,4-cyclohexane dimethanol, 230 g ofadipic acid and 0.4 g of an antioxidant (ADK STAB AO-60) were added, andthese materials were allowed to polymerize for 4 hours under normalpressure with the temperature being slowly increased from 160° C. to200° C. Then, 0.2 g of zirconium acetate was added thereto and allowedto polymerize for 3 hours at 200° C. under reduced pressure, whereby apolyester was obtained. This polyester had an acid value of 14 and anumber-average molecular weight (Mn) of 5,200 in terms of polystyrene.

Next, 300 g of the thus obtained polyester, 150 g of polyethylene glycolhaving a number-average molecular weight of 4,000, 0.45 g of anantioxidant (ADK STAB AO-60) and 0.45 g of zirconium acetate were addedand allowed to polymerize at 200° C. for 5 hours under reduced pressure,whereby a polyether ester comprising hydroxyl groups at both ends wasobtained. This polyether ester had a hydroxyl value of 9 and anumber-average molecular weight (Mn) of 12,200 in terms of polystyrene.

To 200 g of the thus obtained block polymer comprising hydroxyl groupsat both ends, 1.7 g of butane-1,2,3,4-tetracarboxylic dianhydride wasadded as a polycarboxylic acid, and the resulting mixture was allowed topolymerize at 240° C. for 4 hours under reduced pressure, whereby anantistatic agent (E)-2 according to the present invention was obtained.

Production Example 3

To a separable flask, 275 g of hydrogenated bisphenol A, 166 g of adipicacid and 0.4 g of an antioxidant (ADK STAB AO-60) were added, and thesematerials were allowed to polymerize for 5 hours under normal pressurewith the temperature being slowly increased from 170° C. to 200° C.Then, 0.2 g of zirconium acetate was added thereto and and allowed topolymerize for 4 hours at 210° C. under reduced pressure, whereby apolyester was obtained. This polyester had an acid value of 28 and anumber-average molecular weight (Mn) of 2,800 in terms of polystyrene.

Next, 300 g of the thus obtained polyester, 150 g of polyethylene glycolhaving a number-average molecular weight of 2,000, 0.45 g of anantioxidant (ADK STAB AO-60) and 0.45 g of zirconium acetate were addedand allowed to polymerize at 210° C. for 6 hours under reduced pressure,whereby a polyether ester comprising hydroxyl groups at both ends wasobtained. This polyether ester had a hydroxyl value of 4.5 and anumber-average molecular weight (Mn) of 6,100 in terms of polystyrene.

To 200 g of the thus obtained block polymer comprising hydroxyl groupsat both ends, 4.3 g of trimellitic anhydride was added as apolycarboxylic acid, and the resulting mixture was allowed to polymerizeat 240° C. for 4 hours under reduced pressure, whereby an antistaticagent (E)-3 according to the present invention was obtained.

Production Example 4

To a separable flask, 225 g of 1,4-cyclohexane dimethanol, 209 g ofsebacic acid and 0.4 g of an antioxidant (ADK STAB AO-60) were added,and these materials were allowed to polymerize for 4 hours under normalpressure with the temperature being slowly increased from 160° C. to200° C. Then, 0.4 g of zirconium acetate was added thereto and andallowed to polymerize for 4 hours at 200° C. under reduced pressure,whereby a polyester was obtained. This polyester had an acid value of 28and a number-average molecular weight (Mn) of 5,200 in terms ofpolystyrene.

Next, 200 g of the thus obtained polyester, 200 g of polyethylene glycolhaving a number-average molecular weight of 2,000, 0.4 g of anantioxidant (ADK STAB AO-60) and 0.4 g of zirconium acetate were addedand allowed to polymerize at 210° C. for 6 hours under reduced pressure,whereby a polyether ester comprising hydroxyl groups at both ends wasobtained. This polyether ester had a hydroxyl value of 9 and anumber-average molecular weight (Mn) of 12,100 in terms of polystyrene.

To 200 g of the thus obtained block polymer comprising hydroxyl groupsat both ends, 4.3 g of butane-1,2,3,4-tetracarboxylic dianhydride wasadded as a polycarboxylic acid, and the resulting mixture was allowed topolymerize at 240° C. for 4 hours under reduced pressure, whereby anantistatic agent (E)-4 according to the present invention was obtained.

Production Example 5

To a separable flask, 99 g of 1,4-cyclohexane dimethanol, 126 g of1,4-cyclohexane dicarboxylic acid, 150 g of polyethylene glycol having anumber-average molecular weight of 2,000 and 0.35 g of an antioxidant(ADK STAB AO-60) were added, and these materials were allowed topolymerize for 6 hours under normal pressure with the temperature beingslowly increased from 160° C. to 200° C. Then, 0.35 g of zirconiumacetate was added thereto and allowed to polymerize for 5 hours at 210°C. under reduced pressure, whereby a polyether ester comprising hydroxylgroups at both ends was obtained. This polyether ester had a hydroxylvalue of 8 and a number-average molecular weight (Mn) of 13,100 in termsof polystyrene.

To 200 g of the thus obtained block polymer comprising hydroxyl groupsat both ends, 1.6 g of pyromellitic anhydride was added as apolycarboxylic acid, and these materials were allowed to polymerize at240° C. for 4 hours under reduced pressure, whereby an antistatic agent(E)-5 according to the present invention was obtained.

Production Example 6

To a separable flask, 312 g of hydrogenated bisphenol A, 175 g of adipicacid and 0.4 g of an antioxidant (ADK STAB AO-60) was added, and thesematerials were allowed to polymerize for 6 hours under normal pressurewith the temperature being slowly increased from 160° C. to 210° C.Then, 0.2 g of zirconium acetate was added thereto and allowed topolymerize for 5 hours at 210° C. under reduced pressure, whereby apolyester was obtained. This polyester had a hydroxyl value of 28 and anumber-average molecular weight (Mn) of 4,700 in terms of polystyrene.

Next, 200 g of the thus obtained polyester, 200 g of polyethylene glycolhaving a number-average molecular weight of 4,000, 22 g of pyromelliticanhydride as a polycarboxylic acid, 0.4 g of an antioxidant (ADK STABAO-60) and 0.4 g of zirconium acetate were added and allowed topolymerize for 6 hours under reduced pressure with the temperature beingslowly increased from 200° C. to 240° C., whereby an antistatic agent(E)-6 according to the present invention was obtained.

Production Example 7

To a separable flask, 186 g of 1,4-cyclohexane dimethanol, 261 g ofsebacic acid, 12.8 g of trimellitic anhydride as a polycarboxylic acidand 0.4 g of an antioxidant (ADK STAB AO-60) were added, and thesematerials were allowed to polymerize for 5 hours under normal pressurewith the temperature being slowly increased from 160° C. to 210° C.Then, 0.4 g of zirconium acetate was added thereto and allowed topolymerize for 4 hours at 210° C. under reduced pressure, whereby apolyester was obtained. This polyester had an acid value of 28 and anumber-average molecular weight (Mn) of 7,600 in terms of polystyrene.

Next, 150 g of the thus obtained polyester, 100 g of polyethylene glycolhaving a number-average molecular weight of 2,000, 0.2 g of anantioxidant (ADK STAB AO-60) and 0.25 g of zirconium acetate were addedand allowed to polymerize at 240° C. for 6 hours under reduced pressure,whereby an antistatic agent (E)-7 according to the present invention wasobtained.

Production Example 8

To a separable flask, 103 g of 1,4-cyclohexane dimethanol, 123 g of1,4-cyclohexane dicarboxylic acid, 100 g of polyethylene glycol having anumber-average molecular weight of 4,000, 3.3 g of citric acid as apolycarboxylic acid and 0.3 g of an antioxidant (ADK STAB AO-60) wasadded, and these materials were allowed to polymerize for 5 hours undernormal pressure with the temperature being slowly increased from 160° C.to 210° C. Then, 0.3 g of zirconium acetate was added thereto andallowed to polymerize for 4 hours under reduced pressure with thetemperature being slowly increased from 210° C. to 240° C., whereby anantistatic agent (E)-8 according to the present invention was obtained.

Comparative Production Example 1

The polyether ester comprising hydroxyl groups at both ends wassynthesized by the method described in Production Example 1. The thusobtained polyether ester was used as a comparative antistatic agent (1)in Comparative Examples.

Comparative Production Example 2

To a separable flask, 200 g of the polyether ester obtained by themethod described in Production Example 1, 4.1 g of benzoate as amonocarboxylic acid, 0.2 g of an antioxidant (ADK STAB AO-60) and 0.2 gof zirconium acetate were added, and these materials were allowed topolymerize for 5 hours at 240° C. under reduced pressure, whereby anantistatic agent was obtained. This antistatic agent was used as acomparative antistatic agent (2) in a Comparative Example.

Comparative Production Example 3

To a separable flask, 200 g of the polyether ester obtained by themethod described in Production Example 1, 2.8 g of terephthalic acid asa dicarboxylic acid, 0.2 g of an antioxidant (ADK STAB AO-60) and 0.2 gof zirconium acetate were added, and these materials were allowed topolymerize for 5 hours at 240° C. under reduced pressure, whereby anantistatic agent was obtained. This antistatic agent was used as acomparative antistatic agent (3) in a Comparative Example.

Examples 1 to 17 and Comparative Examples 1 to 8

Using antistatic resin compositions that were each blended based on therespective formulations shown in Tables 1 to 3 below, test pieces wereobtained in accordance with the below-described test piece preparationconditions. For each of the thus obtained test pieces, the surfacespecific resistance (SR value) was measured and a test for evaluation ofresistance to wiping with water was conducted as described below. In thesame manner, the resin compositions of Comparative Examples wereprepared in accordance with the respective formulations shown in Table 4below and evaluated.

<Conditions for Preparing Test Pieces of Impact Copolymer PolypropyleneResin Compositions>

Using a biaxial extruder manufactured by Ikegai Corp. (PCM30, equippedwith a 60-mesh screen), antistatic resin compositions that were blendedbased on the respective formulations shown in Tables below were eachgranulated under the conditions of 200° C. and 6 kg/hour to obtainpellets. Then, using a horizontal injection molding machine (NEX80,manufactured by Nissei Plastic Industrial Co., Ltd.), each of the thusobtained pellets was molded at a resin temperature of 200° C. and a dietemperature of 40° C. to obtain a test piece of 100 mm×100 mm×3 mm insize.

<Conditions for Preparing Test Pieces of Homopolypropylene ResinCompositions>

Using a biaxial extruder manufactured by Ikegai Corp. (PCM30, equippedwith a 60-mesh screen), antistatic resin compositions that were blendedbased on the respective formulations shown in Tables below were eachgranulated under the conditions of 230° C. and 6 kg/hour to obtainpellets. Then, using a horizontal injection molding machine (NEX80,manufactured by Nissei Plastic Industrial Co., Ltd.), each of the thusobtained pellets was molded at a resin temperature of 230° C. and a dietemperature of 40° C. to obtain a test piece of 100 mm×100 mm×3 mm insize.

<Conditions for Preparing Test Pieces of ABS Resin Compositions>

Using a biaxial extruder manufactured by Ikegai Corp. (PCM30, equippedwith a 60-mesh screen), antistatic resin compositions that were blendedbased on the respective formulations shown in Tables below were eachgranulated under the conditions of 230° C. and 6 kg/hour to obtainpellets. Then, using a horizontal injection molding machine (NEX80,manufactured by Nissei Plastic Industrial Co., Ltd.), each of the thusobtained pellets was molded at a resin temperature of 230° C. and a dietemperature of 50° C. to obtain a test piece of 100 mm×100 mm×3 mm insize.

<Method for Measuring Surface Specific Resistance (SR Value)>

The thus obtained test pieces were each molded and, immediatelythereafter, stored under the conditions of a temperature of 25° C. and ahumidity of 60% RH. After 1 day and 30 days of storage, under the sameatmosphere, the surface specific resistance (Ω/□) of each molded testpiece was measured using an R8340 resistance meter manufactured byAdvantest Corporation under the conditions of an applied voltage of 100V and a voltage application time of 1 minute. The measurement wasperformed at five spots and an average thereof was determined.

<Test for Evaluation of Resistance to Wiping with Water>

The surface of each of the thus obtained test pieces was wiped with awaste cloth 50 times in running water and subsequently stored for 2hours under the conditions of a temperature of 25° C. and a humidity of60%. Thereafter, under the same atmosphere, the surface specificresistance (Ω/□) was measured using an R8340 resistance metermanufactured by Advantest Corporation under the conditions of an appliedvoltage of 100 V and a voltage application time of 1 minute. Themeasurement was performed at five spots and an average thereof wasdetermined.

TABLE 1 Example 1 2 3 4 5 6 7 Antistatic agent (E)-1 10 10 10 10 10(E)-2 10 (E)-3 10 Alkali metal salt KOAc*¹ 0.5 0.5 NaDBS*² 0.5 LiOTs*³0.5 0.5 Ionic liquid IBTFS*⁴ 0.5 Thermoplastic ICP*⁵ 100 100 100 100 100100 100 resin hPP*⁶ ABS*⁷ Surface specific After 1 day 8 × 10¹² 7 × 10¹⁰8 × 10¹⁰ 5 × 10¹⁰ 2 × 10¹⁰ 8 × 10¹⁰ 9 × 10¹⁰ resistance (Ω/□) After 30days 7 × 10¹² 7 × 10¹⁰ 8 × 10¹⁰ 5 × 10¹⁰ 2 × 10¹⁰ 8 × 10¹⁰ 9 × 10¹⁰Evaluation of resistance to 7 × 10¹² 6 × 10¹⁰ 8 × 10¹⁰ 4 × 10¹⁰ 3 × 10¹⁰9 × 10¹⁰ 8 × 10¹⁰ wiping with water (Ω/□) *¹potassium acetate *²sodiumdodecylbenzenesulfonate *³lithium p-toluenesulfonate*⁴1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide*⁵impact copolymer polypropylene, manufactured by Japan PolypropyleneCorporation: trade name “BC03B” *⁶homopolypropylene, manufactured byJapan Polypropylene Corporationtrade name “MA3” *⁷ABS resin,manufactured by Techno Polymer Co., Ltd.trade name “TECHNO ABS110”

TABLE 2 Example 8 9 10 11 12 13 14 Antistatic agent (E)-1 10 10 (E)-4 10(E)-5 10 (E)-6 10 (E)-7 10 (E)-8 10 Alkali metal salt KOAc*¹ NaDBS*² 0.5LiOTs*³ 0.5 0.5 0.5 0.5 0.5 0.5 Ionic liquid IBTFS*⁴ Thermoplastic ICP*⁵100 100 100 100 100 resin hPP*⁶ 100 ABS*⁷ 100 Surface specific After 1day 1 × 10¹¹ 7 × 10¹⁰ 6 × 10¹⁰ 1 × 10¹¹ 6 × 10¹¹ 5 × 10¹¹ 8 × 10¹¹resistance (Ω/□) After 30 days 9 × 10¹⁰ 7 × 10¹⁰ 5 × 10¹⁰ 9 × 10¹⁰ 6 ×10¹¹ 6 × 10¹¹ 8 × 10¹¹ Evaluation of resistance to 9 × 10¹⁰ 7 × 10¹⁰ 5 ×10¹⁰ 9 × 10¹⁰ 5 × 10¹¹ 5 × 10¹¹ 7 × 10¹¹ wiping with water (Ω/□)

TABLE 3 Example 15 16 17 Antistatic agent (E)-1 7 7 15 Alkali metal saltKOAc*¹ NaDBS*² 0.35 LiOTs*³ 0.75 Ionic liquid IBTFS*⁴ Thermoplasticresin ICP*⁵ 100 100 100 hPP*⁶ ABS*⁷ Surface specific After 1 day 5 ×10¹³ 5 × 10¹² 3 × 10⁹ resistance (Ω/□) After 30 days 5 × 10¹³ 5 × 10¹² 3× 10⁹ Evaluation of resistance to wiping 4 × 10¹³ 4 × 10¹² 2 × 10⁹ withwater (Ω/□)

TABLE 4 Comparative Example 1 2 3 4 5 6 7 8 Comparative (1) 10 10Antistatic agent (2) 10 (3) 10 (4)*⁸ 10 Alkali metal salt KOAc*¹ 0.5NaDBS*² LiOTs*³ Ionic liquid IBTFS*⁴ Thermoplastic ICP*⁵ 100 100 100 100100 100 resin hPP*⁶ 100 ABS*⁷ 100 Surface specific After 1 day 9 × 10¹⁴7 × 10¹⁴ 1 × 10¹⁵ 5 × 10¹⁴ 8 × 10¹⁴ 1 × 10¹⁵ 1 × 10¹⁵ 3 × 10¹⁵resistance (Ω/□) After 30 9 × 10¹⁴ 7 × 10¹⁴ 1 × 10¹⁵ 5 × 10¹⁴ 7 × 10¹⁴ 1× 10¹⁵ 1 × 10¹⁵ 3 × 10¹⁵ days Evaluation of resistance to 8 × 10¹⁴ 8 ×10¹⁴ 1 × 10¹⁵ 4 × 10¹⁴ 7 × 10¹⁴ 1 × 10¹⁵ 1 × 10¹⁵ 3 × 10¹⁵ wiping withwater (Ω/□) *⁸polyether ester amide-based antistatic agent, manufacturedby BASF Japan Ltd.: trade name “IRGASTAT P-22”

From the results shown in the above tables, it is apparent that,according to the present invention, an antistatic agent which is capableof providing excellent antistatic effect in a small amount and hassufficient persistence and wiping resistance can be obtained.

The invention claimed is:
 1. An antistatic agent comprising a polymercompound (E) having a structure in which a diol, a dicarboxylic acid, acompound (B) which comprises at least one group represented by thefollowing Formula (1) and has hydroxyl groups at both ends, and apolycarboxylic acid compound (D) are bound via ester bonds:—CH₂—CH₂—O—  (1) wherein said polymer compound (E) has a structure inwhich a polyester (A), which is constituted by a diol and a dicarboxylicacid, said compound (B) and said polycarboxylic acid compound (D) arebound via ester bonds, and wherein said polymer compound (E) has astructure in which a block polymer (C) having hydroxyl groups at bothends and said polycarboxylic acid compound (D) are bound via an esterbond, said block polymer (C) comprising a block constituted by saidpolyester (A) and a block constituted by said compound (B) that arerepeatedly and alternately bound via ester bonds.
 2. The antistaticagent according to claim 1, wherein said polyester (A) has a structurecomprising carboxyl group at one or both ends.
 3. The antistatic agentaccording to claim 1, wherein said block constituted by said polyester(A) has a number-average molecular weight of 800 to 8,000 in terms ofpolystyrene, said block constituted by said compound (B) has anumber-average molecular weight of 400 to 6,000 in terms of polystyrene,and said block polymer (C) has a number-average molecular weight of5,000 to 25,000 in terms of polystyrene.
 4. The antistatic agentaccording to claim 1, wherein said compound (B) is a polyethyleneglycol.
 5. The antistatic agent according to claim 1, wherein saidpolycarboxylic acid compound (D) is a carboxylic acid having three ormore carboxyl groups.
 6. An antistatic agent composition comprising atleast one selected from the group consisting of alkali metal salts andGroup II element salts in the antistatic agent according to claim
 1. 7.An antistatic resin composition comprising a thermoplastic resin and theantistatic agent according to claim
 1. 8. The antistatic resincomposition according to claim 7, wherein said thermoplastic resin is atleast one selected from the group consisting of polyolefin-based resins,polystyrene-based resins and copolymers thereof.
 9. The antistatic resincomposition according to claim 7, wherein the mass ratio of saidthermoplastic resin and said antistatic agent is in a range of 99/1 to40/60.
 10. A molded article composed of the antistatic resin compositionaccording to claim
 7. 11. An antistatic resin composition comprising athermoplastic resin and the antistatic agent composition according toclaim
 6. 12. The antistatic resin composition according to claim 11,wherein the mass ratio of said thermoplastic resin and said antistaticagent composition is in a range of 99/1 to 40/60.